However, nonlinear effects should be deactivated for test purposes only; for example, to find the causes of model instabilities, since these nonlinearities are sometimes responsible for calculation failures.
Knowledge Base
Deactivation of Nonlinear Effects
If nonlinear effects - such as failing supports, foundations, member nonlinearities, or contact solids - are used in the model, you can deactivate them in the global calculation parameters.
Knowledge Base
Links
- Automatic Generation of Load Combinations in RFEM
- Automatic Generation of Load Combinations in RSTAB
Do you have any questions?
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Supports contributing to a load reduction only under compression or tension can be defined as nonlinear supports in RFEM and RSTAB. It is not always easy for the user to select the correct nonlinearity for "failure under tension" or "failure under compression".
The RFEM5 and RSTAB8 programs offer a "Spring" option when defining a member under the member types.
If nonlinear effects - such as failing supports, foundations, member nonlinearities, or contact solids - are used in the model, you can deactivate them in the global calculation parameters.
In RFEM 5 and RSTAB 8, it is possible to assign nonlinearities to member hinges. In addition to the nonlinearities "Fixed if" and "Partial activity", you can select "Diagram". If you select the "Diagram" option, you have to specify the according settings for the activity of the member hinge. For the individual definition points, it is necessary to specify the abscissa and ordinate values (deformations or rotations and the according internal forces) that define the hinge.
It is possible to specify nonlinearities of member end releases (yielding, tearing, slippage, and so on) and supports (including friction). There are special dialog boxes available for determining the spring stiffnesses of columns and walls based on the geometry specifications.
Result values for deformations, internal forces, stresses, and so on, can be displayed on the isolines.
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Did you know that To calculate masonry structures, a nonlinear material model has been implemented in RFEM. It is based on the approach of Lourenco, a composite yield surface according to Rankine and Hill. This model allows you to describe and model the structural behavior of masonry and the different failure mechanisms.
The limit parameters were selected in such a way that the design curves used correspond to a normative design curve.
RFEM allows you to use a special line hinge to model the special properties of the connection between the reinforced concrete slab and masonry wall. This limits the transferable forces of the connection depending on the specified geometry. You guess right: This means that the material cannot be overloaded.
The program develops interaction diagrams that are applied automatically. They represent the various geometric situations and you can use them to determine the correct stiffness.
How does the "Orthotropic Plastic" material model work in RFEM?
There are two different add-on modules for a response spectrum analysis in RF‑/DYNAM Pro. What can be the reasons for the different results of both add-on modules?
I would like to define a line support with ineffective tension and apply the tension force on this line using a nodal support instead. Why does the line support still receive a tension force?
I obtain different results when comparing the deformation analysis in the RF‑CONCRETE add-on modules and another calculation program. What could be the reason for this?
In a nonlinear structural system, some load cases do not converge. However, load combinations can be calculated without problems. Why?
How can I incrementally apply the load of a load case to the model?
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